1. Field Of The Invention
This invention relates to an apparatus and a method for separating soft, spongy, planar materials in stacks of materials, for example, sliced bread in loaves, and for individually feeding such materials in sequence for the further processing of such materials, for example, in the case of bread slices, for the preparation of sandwiches therefrom.
2. Description Of The Prior Art
As is explained in prior U.S. Pat. Nos. 1,964,085 (F. R. Schmitt) and 2,611,470 (E. A. Rudolph), it is often desirable to be able to mechanically separate individual slices of bread from sliced loaves of bread and to transfer such slices, in sequence, to a conveyor for further processing. The mechanical handling steps involved in the separation and transferring of bread slices involve certain unique problems that arise by virtue of the compressibility and the lack of rigidity of a slice of bread, especially a slice of freshly baked bread. Thus, it is difficult to handle a slice of freshly baked bread by gripping the bread, since the act of gripping the bread will crush the bread, and it is difficult to mechanically handle a slice of bread in any way in which the slice of bread is in an upright, unsupported condition, since, in such condition, the slice of bread is likely to buckle. Further, in any machine for mechanically handling a slice of bread, each bread slice is usually subjected to inertial forces by virtue of the changes in direction of the slice of bread as it progresses along its path of travel through the machine, and these inertial forces normally increase as the speed of the machine is increased, which is commonly done to increase the productivity of the machine, to the point where the inertial forces acting on the slice of bread are sufficient to cause the slice of bread to be moved from its desired position in the machine. Further, unless a slice of bread is stale or very dry, in which condition it is probably already unsaleable, it is normally rather sticky, and does not readily slide with respect to plates, or other mechanical elements that are frequently used in standard machine design practice. The use of vacuum has been proposed as a way to handle limp, fresh bread, but this accelerates the replacement of the carbon dioxide trapped in the bread with oxygen and water vapor which causes the bread to become stale.